Nerves of the Lower Limb

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Muscles of the hip and thigh | Anatomy contents page | Myotomes and dermatomes

Last updated 30 March 2006

Nerves of the Lower Limb

The Lateral Femoral Cutaneous Nerve (p. 385)

This is a direct branch of the lumbar plexus.
It enters the thigh deep to the lateral end of the inguinal ligament, near the ASIS.
It supplies the skin on the anterior and lateral aspects of the thigh.

The Femoral Nerve (pp. 231, 403)

Click here to go to the Femoral Triangle.

This is the largest branch of the lumbar plexus.

It forms in the abdomen within the substance of the psoas major muscle and descends posterolaterally through the pelvis to the midpoint of the inguinal ligament.
It pierces the psoas major muscle and runs inferolaterally within it to emerge between the psoas major and iliacus muscles, just superior to the inguinal ligament
It then passes lateral to the femoral vessels, outside the femoral sheath enclosing them.

The femoral nerve is not contained in the femoral sheath.

After passing distally in the femoral triangle, the femoral nerve divides into several terminal branches, which supply the anterior thigh muscles.
It also sends articular branches to the hip and knee joints and gives several branches to the skin on the anteromedial side of the lower limb.

The Muscular Branches of the Femoral Nerve

The muscular branches are the nerves to: iliacus, pectineus, sartorius and the 4 heads of quadriceps.

The Cutaneous Branches from the Femoral Nerve (p. 385)

The intermediate and medial femoral cutaneous nerves supply the skin on the anterior and lateral aspect of skin.

The Saphenous Nerve (pp. 403, 405)

This cutaneous branch of the femoral nerve descends through the femoral triangle, lateral to the femoral sheath containing the femoral vessels.

The saphenous nerve accompanies the femoral artery in the adductor canal and becomes superficial by passing between the sartorius and gracilis muscles.
It passes anteroinferiorly to supply the skin and fascia of the anterior and medial aspects of the knee, leg and foot.

The Obturator Nerve (pp. 231, 259)

It arises from the lumbar plexus in the abdomen.

This nerve descends though the psoas major muscle, leaving its medial border at the brim of the pelvis.
It pierces the psoas fascia, crosses the sacroiliac joint, passes lateral to the internal iliac vessels and ureter, and enters the pelvis minor.
The obturator nerve leaves the pelvis through the obturator foramen and enters the thigh.

The obturator is the nerve to the adductor muscles of the thigh.

The Muscular Branches of the Obturator Nerve

This nerve sends branches to: obturator externus, pectineus, adductor longus, adductor brevis, gracilis and the adductor part of adductor magnus.

The Cutaneous Branches of the Obturator Nerve

This cutaneous branch of this nerve supplies the medial side of the thigh.

The Posterior Femoral Cutaneous Nerve (p. 413)

This is a posterior cutaneous nerve of the thigh and it arises from the posterior divisions of the ventral rami of S1 and S2 and the anterior divisions of S2 and S3.

It supplies more skin that any other cutaneous nerve.

This nerve leaves the pelvis with the inferior gluteal nerve and vessels and the sciatic nerve.
Its fibres from the posterior divisions supply the skin of the inferior of the buttock.
The anterior fibres supply the skin of the perineum.
Other branches supply the skin of the posterior thigh and proximal part of the leg.

The Nerve to Quadratus Femoris Muscle (p. 413)

This nerve arises from the anterior divisions of the ventral rami of L4, L5 and S1.

It leaves the pelvis deep (anterior) to the sciatic nerve and the obturator internus muscle and passes over the posterior surface of the hip joint.
It supplies an articular branch to this joint and innervates the quadratus femoris and inferior gemellus muscles.

The Nerve to the Obturator Internus (p. 417)

This nerve arises from the anterior divisions of the ventral rami of L5, S1, and S2.

It leaves the pelvis through the greater sciatic foramen, inferior to the piriformis muscle and medial to the sciatic nerve.
It winds around the base of the ischial spine to supply the superior gemellus muscle.
It then passes posterior to the ischial spine, re-entering the pelvis via the lesser sciatic foramen. It lies on the lateral pelvic wall and supplies the obturator internus muscle.

The Inferior Gluteal Nerve (p. 413)

This nerve arises from the posterior divisions of the ventral rami of L5, S1, and S2.

It leaves the pelvis through the inferior part of the greater sciatic foramen, inferior to the piriformis muscle and superficial to the sciatic nerve.
It accompanies the inferior gluteal artery and breaks up into several branches that supply the overlying gluteus maximus muscle.

The Superior Gluteal Nerve (p. 413)

This nerve arises from the posterior divisions of the ventral rami of L4, L5, and S1.

It leaves the pelvis through the superior part of the greater sciatic foramen, superior to the piriformis muscle, with the superior gluteal artery.
It runs laterally between the gluteus medius and minimus muscles with the deep branch of the superior gluteal artery.

The superior gluteal nerve divides into a superior branch that supplies the gluteus medius and an inferior branch that passes between the gluteus medius and gluteus minimus mm.

The superior gluteal nerve also supplies the tensor fasciae latae.

The Sciatic Nerve (p. 413)

This is the main branch of the sacral plexus.
This is the largest nerve in the body and is formed by the ventral rami of L4-S3, which converge at the inferior border of the piriformis muscle.

The sciatic nerve leaves the pelvis as a thick, flattened band (about 2 cm wide) and travels through the inferior part of the greater sciatic foramen.
It enters the gluteal region inferior to the piriformis muscle and is the most lateral of all the structures emerging inferior to the piriformis.
It runs inferolaterally deep to the gluteus maximus muscle, midway between the greater trochanter of the femur and the ischial tuberosity.
The sciatic nerve rests on the ischium and then passes posterior to the obturator internus, quadratus femoris, and adductor magnus mm.

The sciatic nerve usually supplies no structures in the gluteal region.
The sciatic nerve is really two nerves, the tibial and common peroneal, which are bound together by the same connective tissue sheath.

The nerves usually separate from each other about halfway or more down the thigh, but occasionally they are separate when they leave the pelvis. In this case, the tibial nerve passes inferior to the piriformis and the common peroneal passes through or superior to it.
Usually, the sciatic nerve divides to its two terminal branches near the apex of the popliteal fossa.

The Muscular Branches of the Sciatic Nerve

The sciatic nerve supplies the hamstring muscles as well as the ischial head (hamstring part) of the adductor magnus.

The Tibial Nerve (p. 429)

This is the medial terminal branch of the sciatic nerve.
It is the most superficial of the three main central components of the popliteal fossa (i.e., nerve, vein and artery).
It lies immediately deep to the popliteal fascia.

At first, the semimembranosus muscle covers the tibial nerve. It then passes obliquely, superficial to the popliteal vessels, and comes to lie medial to them, where it is covered by the converging heads of the gastrocnemius muscle.

This nerve supplies all the muscles in the posterior compartment of the leg.

The tibial nerve descends though the middle of the popliteal fossa, posterior to the popliteal vein and artery.
At the distal border of the popliteus muscle, the tibial nerve passes with the posterior tibial vessels deep to the tendinous arch of the soleus muscle.
It then descends straight down the medial plane of the calf, deep to the soleus.
It runs inferiorly on the tibialis posterior muscle, in company with the posterior tibial vessels.
The tibial nerve leaves the posterior compartment of the leg by passing deep to the flexor retinaculum in the interval between the medial malleolus and calcaneus.
The tibial nerve lies between the posterior tibial vessels and the tendon of the flexor hallucis longus.

Posteroinferior to the medial malleolus, the tibial nerve divides into the medial and lateral plantar nerves.

The Sural Nerve (p. 458)

This is formed from a cutaneous branch of the tibial, the medial sural cutaneous nerve and the communicating branch from the common peroneal nerve.
This nerve supplies the skin of the lateral and posterior part of the inferior third of the leg and the lateral side of the foot.

The Common Peroneal (Fibular) Nerve

This is the lateral and smaller of the two terminal branches of the sciatic nerve.

The common peroneal nerve usually begins at the superior angle of the popliteal fossa and follows the medial border of the biceps femoris muscle and its tendon along the superolateral boundary of the popliteal fossa.
It leaves the fossa by passing superficial to the lateral head of the gastrocnemius muscle.
The common fibular nerve then passes over the posterior aspect of the head of the fibula before winding around the lateral surface of the neck of this bone.
It then runs deep to the superior part of the fibularis longus muscle.

It is palpable where it winds around the neck of the bone.
In this region the nerve ends by dividing into the superficial and deep peroneal nerves.

Within the popliteal fossa (before dividing), this nerve gives off the lateral sural cutaneous nerve to the skin of the calf and the peroneal communicating branch.

The Deep Peroneal Nerve (pp. 446-7)

This is the nerve of the anterior crural compartment.

It begins between the fibula and the superior part of the fibularis longus muscle.
It then runs inferomedially on the fibula, deep to the extensor digitorum longus.
After piercing the anterior crural intermuscular septum and the extensor digitorum longus, the deep peroneal nerve descends anterior to the interosseous membrane in the anterior crural compartment.
It accompanies the anterior tibial artery between the extensor hallucis longus and tibialis anterior muscles.

It supplies the muscles in the anterior compartment.
It also supplies the skin between the first and second toes.

The Superficial Peroneal Nerve (p. 449)

This is the nerve of the lateral compartment of the leg.

This nerve begins between the fibularis longus muscle and the fibula and descends posterolateral to the anterior crural intermuscular septum.
It lies anterolateral to the fibula between the fibular muscles and the extensor digitorum longus.
The superficial peroneal nerve supplies the fibularis muscles and then pierces the deep fascia to become superficial in the distal third of the leg.

It passes in the superficial fascia to supply the skin on the distal part of the anterior surface of the leg, nearly all the dorsum of the foot and most of the digits.